Oasis Horse

Character Breakdown

Adarsh Shetty

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Adarsh Shetty

3D Artist

Introduction

Hello! My name is Adarsh. I am a Character and Prop artist from the UK. I like creating game-ready characters, creatures, and props that further the narrative, weaving together a tale of visual storytelling. I have received my master’s degree in Game Art from Sheffield Hallam University. I have a bachelor’s degree in Mechanical Engineering with four years of experience as a product designer in India.

For my master’s project, I decided to build upon the project, Mercury, which was a series of artifacts fitting a steampunk theme. To create an all-encompassing narrative, I created another character from the universe, Mercury’s trusted travel companion called Oasis.

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In this article, I will be showcasing the creation of Oasis and his accessories. I will elaborate the techniques, challenges, and methods of optimization I used to overcome them.

Concepting and Pre-Production

I like creating concepts and building narratives before diving into the 3D pipeline. This helps embed the narrative into the creative workflow. When I first created the concept of Oasis, it was called the Equine Ornithopter- Oasis, one of the biggest pieces from the universe of Mercury. Oasis, the horse, is the name of Mercury’s trusted companion.

Equipped with a steampunk Ornithopter (winged armature), one of Mercury’s inventions, Oasis transforms into a cruiser chariot for Mercury’s aerial voyages.

The idea was unfortunately unrealistic to execute from a timeline point of view. So, I decided to replace the ornithopter with a series of assets: a hat, a lantern, a water canteen, and a rope bundle.

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The perfect start to any character project is having an in-depth understanding of the subject’s anatomy. I realized how nuanced the knowledge of equine anatomy is when I needed it during the concepting phase.

Hence, I invested a substantial amount of time in gathering references of horses of similar form, creating a library of horse skeletal anatomy, musculature, skin shades, fur propagation, hide textures, hair textures, hoof textures and eye textures, and color composition.

Including references from various in-game models for popular games like The Last of Us 2, Red Dead Redemption 2, and other game-ready horses from Artstation. This in-depth study helped me bring about realism to the concept along with the sculpts and textures.

I narrowed the horse reference down to one thoroughbred racehorse called Daddy Long Legs with prominent features like chestnut hide, white ankle stockings, golden brown hair, and brown and white fur patches.

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The first inspiration was drawn from the horses in the popular game ‘The Last of Us’ designed by Priya Johal.

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High-Poly Creation of Oasis

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The lack of composite tutorials and production documents for the elements involved in my project was a challenge. After exploring several avenues, I landed on broaching the subject by studying horse anatomy. Luckily, I found websites outlining all aspects of equine physiology and anatomy.

One beneficial website catering to horse equipment and health is called ‘Equishop’: https://www.equishop.com/en/blog/horse-anatomy-body-parts-muscles-skeleton-n299. The website described the horse’s musculature and skeletal proportions in detail.

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The hoof of a horse is a complex part of the design as it adds a touch of realism and provides personality to the character. I paid special attention to the design by referring to a horse health website for the hoof anatomy and reference images. https://www.horsehealthproducts.com/horsemans-report/hoof-leg-care/hoof-anatomy.

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A vital piece that brought the whole picture together was a website by Leah Koerper called ‘Shoestring Stable’.

This website is dedicated to DIY-style miniature horse modeling. Since the website has artistic origins, the author meticulously put together multiple close-up images of various horse body parts.

Images of musculature and skeletal anatomy were available from all views. The information on a fur coat and hair growth patterns were also pictorially depicted. The information on hair growth patterns helped me realistically texture the fur coat into the material maps. It was a great jumping-off point to get accurate proportions and skin texture patterns for the final model.

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I closely referred to a thoroughbred racehorse owned by Michael Tabor, Derrick Smith, and Mrs. John Magnier called Daddy Long Legs. The stallion was the closest in physique and chestnut coat to my original concept.

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Artstation was a great source of research on 3D models and renders of horse anatomy. One such example of an accurate 3D model of equine anatomy was by Farzin Izadyar.

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Another reference to the same was by Dmitrii Prosov.

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A great reference for the finished product including the additional elements of the saddle pack, reins, stirrups, and harness was designed by Pogar Marius as part of an asset pack.

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After compiling all the available information, I created a base mesh of Oasis in Zbrush of appropriate shape, size, and form.

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I built the sculpt of Oasis up from a sphere and added skeletal details, musculature, skinfolds, and veins layer by layer. To that, details like pores and cracks on the face, scratches and cracks on hooves, and primary fur coat were added onto the body.

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Next, I focused on the eyes. The general process of creating looks is to use a flat texture for the iris and sclera, create height maps using the surface in Zbrush for high poly and then bake it over the low poly model. Unfortunately, the eye textures for horses were not readily available.

So, I resorted to manually sculpting the iris in the high poly model, referring to close-up references of horse eyes in Zbrush.

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A distinguishing feature of the horse eye is the nictitating membrane or the third eyelid which I modeled in Zbrush and the equivalent low poly models in Maya.

One resource that was particularly useful for realistic hair is Female Bust Course in Marmoset Toolbag by David Zavala. Using Zbrush’s fibermesh, I created 6 different hair patterns with variations in density and flow and arranged them in a 4K square black background render view to fit into the UV space. I created the hair cards in Maya.

I then placed a combination of these cards with varying sizes on the horse head, neck, and tail in Zbrush and refined it using move topology brush. I also gave the arranged cards a gravity simulation inside Dynamics using horse body as the collision object.

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Back in Maya, I moved the cards using soft selection and then smooth the edges. In Photoshop, I created the normal map for the hair and a simple gradient which acted normal and albedo while texturing hair.

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High-Poly Creation of Accessories

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I finalized the list of accessories as face harnesses, reins and belts, saddles, stirrups, satchels, duffle bags, luggage bags, hats, water canteen, rope bundles, and lanterns with most of the assets either leather, cloth or metal.

On the back of the horse lies the saddle with hanging stirrups. The leather on the saddle has features like embroidery, threadwork, jewelry buttons, etc. Additionally, there is a chesterfield pattern for the rest cushion. Placed on the rear back of the horse is a luggage kit containing two satchels, two duffle bags, one big luggage, a jute rope bundle, an old lantern and a jute fabric water canteen.

The highlighting features of the luggage kit are large sheets of leather, embroidery, metallic emblems, and belts. The significant feature of the hat is a fabric braid and a metal emblem. The assets tailor the narrative of a traveler armed with essentials. The crux of the project is to convey utility, usage, and wear through the assets.

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I modeled the base mesh for assets like hats, saddle lanterns, and canteen in Maya using hard surface modeling techniques. The lantern was the only asset where I reused the base mesh as low poly for baking.

Since the majority of the assets were organic, I had to find creative ways to retopologize. As fitting these assets on the horse involves a variety of deformations that cannot be accounted for in the base mesh creation stage, requiring a post-high poly treatment.

For assets like belts, reins, harnesses, and ropes, I used the sweep curve feature with respective cross sections suited for the design. For the rope, I wound multiple cross-sections in the form of a helix to achieve a realistic rope. The same guides were used to create a cylindrical low poly which I carried to Zbrush to retain the deformation.

I manually arranged the curves to manufacture the randomness in all these assets. The design of many of the assets had some semblance of symmetry and hence I relied on the mirror function of Zbrush. The advantage of creating assets on a giant quadruped is that both sides can never be viewed simultaneously.

This implies that I need only unwrap and texture one-half of the assets. For embroidery on leather, stitches, and the braid on the hat I created various IMM brush instances in Zbrush and used the curve function to run it across the desired path.

The majority of the low poly was created using quad draw. Features like embroidery, stitches and other details were baked from high poly. I removed the back faces on several assets which were more likely to be always hidden to save the poly count. Holes on models with no back faces were directly introduced using opacity maps in the texturing phase.

Low-Poly Creation: Retopology and Unwrapping

For the horse, using a slightly lower subdivision level, I created a low poly retopology using a combination of Zremesher in Zbrush and Quad draw in Maya. Using Zremesher guides, I manipulated the flow of new topology.

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I added loops around eyes, nostrils, mouth, ears, and propagation edge loops along the length of the limbs, neck, and torso to make the horse suitable for rigging in Maya. The poly count for the low poly is 9396 polys.

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I added seams on the horse around the neck, ears, limbs, tail, and hoof edges and one along the length to open up the UVs. I then unwrapped the UVs along the seams and arranged them proportionately in a 0 to 1 UV space.

For the assets, however, I relied completely on the use of quad draw. I imported a relatively lower subdivision model into Maya and created a fresh topology using the high poly as a live surface. My approach to unwrapping and texturing low poly assets was to treat each asset as a hero prop and therefore assign a UV and texture space for each of them. Here is how I combined models into assets sharing UV space.

Below are the UVs for the horse, eyes, eyelashes, forehead hair, neck hair, tail hair, canteen, lantern, hat, ropes, face harness, reins and belts, horseshoe, duffel bags, luggage, saddle, stirrups, saddle cloth and the satchel. In that order.

After smoothening the edges, cleaning up the mesh and matching vertex normals to face normals, I moved onto texturing.

Baking and Texturing

I found tutorials on human skin texturing in abundance but none elaborating on fur texture creation for animals for the quality I intended. In the pre-production phase of the project, I experimented with horse hide textures using Substance Painter. This practice really helped me pull off details like fur, roughness variation, color composition, and anisotropic specularity in the production phase.

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As I was aiming for realism, it was important to get the fur and eye textures to the maximum quality so that when they interacted with light, they had to appear believable. I started off by baking high poly texture maps onto low poly in substance painter.

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With that, I stacked up layers following the steps outlined below:

1)Rough base skin with dark patches around skin folds and light patches around exposed areas.

2) Using curvature and ambient occlusion from the sculpted fur layer gives a little bit of shine to break the base skin roughness.

3) Painting micro fur details in Substance Painter on top of the sculpted fur to enhance the effect slightly. I created alphas from close-up fur images and with a combination of brush and stencil, I then painted on the first layer.

4) Using this method I created two fur layers, one following the fur growth direction closely and the other very sparse in random directions to give the natural fuzzy feel. I gave a very contrasting shine to these fur layers to make them stand out from the rough base and to also break the anisotropy that I was planning on introducing in Marmoset Toolbag later.

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5) To give these fur layers a bit of depth, I used anchor points to introduce ambient occlusion to the painted layers.

6) I provided varying color values to bring about the chestnut effect and a contrasting light color value to the topmost sparse fur for highlighting.

7) To give the hide a bit of character, I introduced features like white ‘ankle stocking’ fur, white fur patches on the face and torso along with moles on the body.

8) For hooves, I created a dull shiny wood-like material with mud and grime with subsurface scattering using a thickness map to derive the keratin-like effect.

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To make the eyes, I baked the high poly eye sculpts onto the low poly in substance painter. The sclera, Iris, and pupil were one mesh while the cornea was another with a nictitating membrane as the outermost layer.

I added transparency to the nictitating membrane and cornea. Textures of the iris and blood vessels were painted on the sclera using photoshop, substance painter and reference images. I added a veiny normal map to the cornea for a bumpy feel instead of a glass ball effect.

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For hair, I used the alpha from the Zbrush fibermesh render and then generated the normal map in Photoshop. Using the same Alpha, a height map in photoshop for ambient occlusion mask was created. For albedo, I used a desaturated gradient mask and added the color in Marmoset. Finally, anisotropy, gloss, specularity and transparency over the alpha were given.

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The primary material of the accessories was leather, metal, jute, and cloth materials. An invaluable trick that I learned for the realistic treatment of props is to give them sufficient roughness breakdown. For albedo, I built layers.

The base layer had minimum details and basic color and roughness information. Then I added layers that gave texture to the asset like cracks and scratches on leather, an intermediate paint layer on metal, a fabric pattern for the cloth and a jute fibrous pattern for rags. High-quality reference images were used to paint on these intermediate layers after combining them in Photoshop.

Topping these layers details like deformation, scratches, wear, grunge, dirt, etc. were added. I utilized curvature and ambient occlusion texture maps to bring about these effects using masks and generators.

I broke the procedural effect by adding masks and painting. Embroidery effects and threadwork on leather and emboss on metal and jewelry were baked down from high poly. To ensure the assets stood out while also not undermining the horse textures, I had to work on color composition by taking trial renders.

Lighting, Rendering and Post-Production

I moved onto rendering the assembly using Marmoset Toolbag. With ray tracing, ambient occlusion, shadows, reflections, and post-processing effects such as slight amounts of vignette, bloom and contrast enabled.

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For tone mapping, a handy trick I gathered was to use ACES as this closely resembles a real-time game engine tone mapping. It is also essential to use similar tone mapping display settings in Substance Painter as well to get the final rendered results as close as the created textures.

I used a free ACES add-on for substance painter on Gumroad by Brian Leleux which modifies the tone mapping to match ACES Unreal Engine 4 color profile https://bleleux.gumroad.com/l/lHiVg.

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The low poly assembly was imported into Marmoset Toolbag after manipulating the limbs to create a standing pose in Maya. With a basic light setup, I created the materials for each asset. For the horse, to give the fur coat a realistic shiny yet rough effect, I introduced anisotropy using a flow map.

Anisotropy without flow maps tends to reveal the UV seams in the mesh. An interesting insight offered by the game developer at Ready at Dawn games showed how to use Mari’s vector paint to create flow maps. To find an alternative to using Mari, I figured out a trick to create flow maps using a combination of Photoshop and substance painter.

1) Flow Map Painting by Substance 3d Painter.
2) Comb Map Creation by Ben Mathis.
3) How to paint flow/anisotropic/comb maps in Photoshop by Polycount.

After several trials using these techniques, I got the flow map to derive the intended anisotropic effect. To diffuse the sporadic thin bands of shine on the fur, I used a combination of effects like gloss, clearcoat specularity, Fresnel, and fuzz. To enhance the effect further, I modified the material to include detail normals, anisotropic reflection and cavity occlusion.

An optimal balance between anisotropy and specular intensity was necessary to give the fur a rough yet shiny appeal. Using a thickness map, I added subsurface scattering to the ears, nostrils, and hooves.

Horse Material

The cornea of the eye has a convex bulge laying over the concave part of the sclera (iris and pupil). Due to the high refractive index of the cornea, the underlying parts appear convex as well. To make eyes look as real as possible, it was necessary to anatomically mimic these effects rather than create a convex sclera.

The concavity of the sclera allows it to catch the light on the valleys of the iris while also appearing convex due to the cornea. Replicating this magical effect was quite a challenge in Marmoset Toolbag.

The trick was to introduce parallax normals, volumetric scattering, and specularity to the sclera while adding refraction/refractive index, gloss, and specularity along with transparency to the cornea. Some of the resources that helped me achieve this result were:

  1. Alfred Roettinger Realtime Eye.
  2. How to Create Realistic Hair, Peach Fuzz, and Eyes by Vadim Sorici.
  3. How to create Realistic Eye Shader in Marmoset Toolbag 4 by Aditya Anand.

Below is the cornea & sclera material.

Simple transparent cornea vs realistic cornea material setup:

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I used a combination of specular, gloss, anisotropy, and transparency along with clearcoat settings. The objective here was to give the hair a wiry effect with a little bit of shine similar to real life horsehair.

Below is the hair, luggage and lantern material.

The final step was setting up the lights. I focused on rim lights to capture the anisotropic shine in all the rendered views. In addition to this, I set up fill and key lights as well as global illumination light sources. With that, I moved on to rendering Oasis.

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Conclusion

The pre-production activities took nearly a month and a half of my university term time, which involved ideation, research, concepting, testing of texturing, learning new tools and professional documentation of the R&D. The production and post-production activities spanned the following 3 months.

Through this project, I aimed to accomplish high-quality sculpts and textures with a realistic presentation. One of the challenges I faced was creating good-quality fur. The lack of resources warranted manually painting for the majority of the textures to enhance the texture quality.

Another challenge was the color composition. Since most of my assets were leather-based, it blended with a chestnut shade of horse hide. Achieving the right appeal within that narrow bandwidth took multiple attempts at texturing and rendering. Creating flow maps for anisotropy was quite challenging as well. It involved a lot of research and experimentation.

Integral advice I received that help me tide over was that polished work is produced through feedback. If I were to put forth the best advice, it would be to put your work in front of as many artists as you can and take on board directional feedback instead of aiming in the dark.

Although the internet can be a vast resource, sometimes a question is best answered through expertise. Establishing a solid network of like-minded people and industry professionals can lubricate this process.

I referred considerably to the in-game horse and saddle kit images from Red Dead Redemption 2 and The Last of Us 2. I tried to match the design proficiency and quality level. I believe the results supersede my initial expectations.

I received a lot of constructive feedback from my university mentor Jonathan Pearmain throughout this journey. His guidance and hands-on support were vital for me to understand the nuances of Game Art. Thank you, Jono!

I would also like to thank my project supervisor Jamie Gibson for guiding me and helping me understand the intricacies of anatomy. Finally, thanks to all the Sheffield Hallam Game Art faculty, Phil Morris, Martin Jones and Tom Battey, for all your support this past year.

Thank you for reading. I hope you enjoyed the creation of Oasis!